The present invention relates generally to pneumatic tools. More particularly, this invention pertains to a pneumatic tool having a handle rotatably connected to the tool and including a locking mechanism for locking the handle in a desired position with respect to the tool.
Many tools, including pneumatic tools, currently used in various industries include handles that are rigidly connected to the housing of the tool. In many practical work situations where a person is using one of these tools, the location of the handle and the fact that the handle cannot be rotated with respect to the housing prevents the use of the tool. This fact has been recognized by people working with such tools and has resulted in the development of tools having handles rotatably connected to a tool housing.
For example, U.S. Pat. No. 5,466,183 issued to Kirn et al. on Nov. 14, 1995 for a xe2x80x9cHand Held Power Tool With Locking Rotatable Appendagexe2x80x9d and U.S. Pat. No. 5,681,214 issued to Kleider et al. on Oct. 28, 1997 for a xe2x80x9cHand Power Toolxe2x80x9d disclose a portable power tool having a handle that is rotatably connected to the housing of the power tool. According to the ""183 and ""214 patents, the handle may be fixed in three (3) different rotational positions relative to the housing of the power tool using three pairs of rib structures. The ""183 and ""214 patents do not disclose or suggest a structure that may be used to fix the handle in more than three (3) rotational positions. Furthermore, the use of pairs of rib structures to fix the position of the handle limits the overall number of positions in which the handle may be fixed. As a result, this tool limits the number of positions that the handle may be fixed in with respect to the tool housing.
Another patent, U.S. Pat. No. 5, 924,497 issued to Spooner et al. on July 20, 1999 for a xe2x80x9cPower Hand Tool With Rotatable Handle,xe2x80x9d discloses a pneumatic tool having a handle rotatably connected to the tool housing. The ""497 patent discloses a handle that is rotatably connected to a pneumatic tool housing using a ring, flange, and wavey spring configuration. The wavey spring forces the handle against the ring and the flange and thereby holds the handle in a fixed position relative to the housing. The ""497 patent teaches that the spring should be chosen to provide enough force to hold the handle in a fixed position while working with the pneumatic tool, but be light enough that an operator may rotate the handle to any desired position.
Although at first glance the ""497 patent seems to provide a solution to the limitation of the ""183 and ""214 patents discussed above, the tool disclosed in the ""497 patent exchanges one disadvantage for another. Specifically, there are situations in which the forces applied to the handle as a result of using a tool connected to the handle may exceed the force provided by the spring to hold the handle in place. In such a situation, the handle would unexpectedly move from its desired position. As a result, a person using the tool may be unable to complete their work or, in more serious situations, the person may be injured when the handle unexpectedly rotates. Thus, although the ""497 patent does disclose a handle than may be fixed in a greater number of positions than the tool disclosed in the ""183 and ""214 patents, the ""497 patent does not disclose a structure or method for securing locking the handle in a desired position.
In still other cases, some tools do not have a handle and simply include a pneumatic control lever for controlling the tool that is rigidly connected to the tool body. For example, one pneumatic tool manufactured by the inventor of the present invention includes a thumb actuated control lever rigidly attached to the left side of the tool body. The tool is designed to be used by an operator by gripping the tool body with the right hand and activating the control lever using the thumb of the operator""s right hand. As a result, this tool is more conveniently used by an operator who is right-handed. In addition, this tool, and all pneumatic tools having a control lever rigidly attached to the tool body for that matter, cannot be used in situations where the location of the control lever prevents the use of the tool.
Accordingly, there is a need for pneumatic tool assembly that includes a handle and control lever rotatably connected to the tool housing, while at the same time, providing a means for securely fixing the handle in a large number of desired positions with respect to the tool housing.
One object of the present invention is to provide a pneumatic tool having a handle and control lever rotatably connected to the tool housing.
Another object is to provide a locking mechanism for locking the handle in multiple positions with respect to the tool housing.
A further object is to provide a pneumatic tool that includes a handle that may be used by an operator that is right-handed or left-handed.
To satisfy these objectives, the present invention includes a swivel backhead connected to a handle and a retainer ring for connecting the swivel backhead to a pneumatic tool. Rotation of the swivel backhead with respect to the pneumatic tool is facilitated by placing a first slip ring in between the swivel backhead and the pneumatic tool. Rotation of the swivel backhead with respect to the retainer ring is facilitated by placing a second slip ring between the swivel backhead and the retainer ring. A locking mechanism, which includes a hand retractable spring loaded plunger that is connected to a swivel lock bracket, is used to fix the swivel backhead, and as a result the handle that is connected to the swivel backhead, at a desired position with respect to the pneumatic tool. Finally, a pneumatic control assembly is connected to the handle and the swivel backhead and operable to control the pneumatic tool.